<?php
$atributos = array('type' => 'hidden', 'name' => 'txt_opcion', 'id' => 'txt_opcion', 'value' => 2); 
echo form_input($atributos);
?>

<div class="form-group">
    <label for="txt_clave" class="col-sm-3 control-label">Clave actual</label>
    <div class="col-sm-5">
      <?php
      $atributos = array('type' => 'password',
                         'class' => 'form-control', 
                         'name' => 'txt_clave_actual',
                         'id' => 'txt_clave_actual',
                         'placeholder' => 'Clave',
                         'required' => 'required',
                         'value' => ''); 
      echo form_input($atributos);
      ?>
    </div>
</div>

<div class="form-group">
    <label for="txt_clave" class="col-sm-3 control-label">Clave nueva</label>
    <div class="col-sm-5">
      <?php
      $atributos = array('type' => 'password',
                         'class' => 'form-control', 
                         'name' => 'txt_clave',
                         'id' => 'txt_clave',
                         'placeholder' => 'Clave',
                         'required' => 'required',
                         'value' => ''); 
      echo form_input($atributos);
      ?>
    </div>
</div>

<div class="form-group">
    <label for="txt_clave_confirmar" class="col-sm-3 control-label">Confirmar Clave</label>
    <div class="col-sm-5">
      <?php
      $atributos = array('type' => 'password',
                         'class' => 'form-control', 
                         'name' => 'txt_clave_confirmar',
                         'id' => 'txt_clave_confirmar',
                         'placeholder' => 'Clave',
                         'required' => 'required',
                         'value' => ''); 
      echo form_input($atributos);
      ?>
    </div>
</div>